2. Which of the following sentences is written correctly?

A When properly designed, an automobile can achieve great fuel efficiency.
B. When properly designed an automobile can achieve great fuel efficiency.
C. When properly designed, great fuel efficiency can be achieved by an automobile.
D. When properly designed great fuel efficiency can be achieved by an automobile
I thank B is the correct answer

No

A is the correct answer

Yes

Thank you again

To determine which sentence is written correctly, let's analyze the options:

A. When properly designed, an automobile can achieve great fuel efficiency.
This sentence is grammatically correct as it includes a comma after "designed." The subject "an automobile" and the verb "can achieve" are appropriately placed.

B. When properly designed an automobile can achieve great fuel efficiency.
This sentence is missing a comma after "designed." The absence of a comma makes the sentence grammatically incorrect.

C. When properly designed, great fuel efficiency can be achieved by an automobile.
This sentence is grammatically correct. It includes a comma after "designed" and uses a passive construction "can be achieved."

D. When properly designed great fuel efficiency can be achieved by an automobile.
Similar to option B, this sentence is missing a comma after "designed." Thus, it is grammatically incorrect.

Therefore, the correct answer is option A: "When properly designed, an automobile can achieve great fuel efficiency."