Select the sentence which is correctly punctuated.

A) His step-daughter is 13 years old.
B) His stepdaughter is 13 years old.

I answered A

I really meant B sorry about that:)

B is right.

To make sure I was right, I Googled "stepdaughter" and checked the dictionary.

Thanks :) I had to check too

The correct answer is B) His stepdaughter is 13 years old.

To determine the correct answer, you need to understand the rules for punctuating compound words. In this case, the compound word is "stepdaughter." When a compound word consists of two words joined together with a hyphen, as in "step-daughter," it is considered hyphenated. On the other hand, when the two words are written together without a hyphen, as in "stepdaughter," it is considered a closed compound word.

In contemporary usage, the trend is to move away from hyphenating compound words. Therefore, the correct and more modern way to write this sentence is to treat "stepdaughter" as a closed compound word without a hyphen. Hence, the correct sentence is B) His stepdaughter is 13 years old.