What is the BEST way to combine the information in the two sentences below?

Mercedes threw Andrea a surprise birthday party last night. Andrea is Mercedes' best friend.
A.
Mercedes threw Andrea, Mercedes' best friend, a surprise birthday party last night.
B.
Mercedes threw Andrea a surprise birthday party last night, when Andrea is Mercedes' best friend.
C.
Mercedes threw Andrea a surprise birthday party last night, Andrea is Mercedes' best friend.
D.
Mercedes threw Andrea a surprise birthday party last night, but Andrea is Mercedes' best friend.

A. Mercedes threw Andrea, Mercedes' best friend, a surprise birthday party last night.

The best way to combine the information in the two sentences is:

Mercedes threw Andrea, Mercedes' best friend, a surprise birthday party last night.

To determine the best way to combine the information in the two sentences, we need to ensure that the information is accurately and clearly conveyed.

Let's break down the information:

- Mercedes threw Andrea a surprise birthday party last night.
- Andrea is Mercedes' best friend.

Now, let's analyze each option:

A. "Mercedes threw Andrea, Mercedes' best friend, a surprise birthday party last night."
This option accurately conveys the information that Andrea is Mercedes' best friend, but the placement of the phrase "Mercedes' best friend" can be improved for better clarity. It is more common to place such descriptors immediately after the person they are describing. So we can rephrase it as: "Mercedes, Andrea's best friend, threw her a surprise birthday party last night."

B. "Mercedes threw Andrea a surprise birthday party last night, when Andrea is Mercedes' best friend."
This option incorrectly emphasizes the timing of the party in relation to their friendship. The original sentences do not suggest any causal relationship between the party and their status as best friends, making this option less accurate.

C. "Mercedes threw Andrea a surprise birthday party last night, Andrea is Mercedes' best friend."
This option is almost correct, but it lacks a conjunction or transition word to connect the two pieces of information. To improve clarity, we can use a conjunction like "and" to link the two statements: "Mercedes threw Andrea a surprise birthday party last night, and Andrea is Mercedes' best friend."

D. "Mercedes threw Andrea a surprise birthday party last night, but Andrea is Mercedes' best friend."
This option introduces a contrasting conjunction "but," which implies some conflicting or opposing relationship between the two statements. However, in this context, the information that Andrea is Mercedes' best friend does not conflict with the fact that Mercedes threw her a surprise birthday party. Therefore, this option is not suitable.

Considering the analysis above, the best way to combine the information in the two sentences is option A: "Mercedes, Andrea's best friend, threw her a surprise birthday party last night." This option accurately and clearly conveys the information.