Determine whether the underlined portion of the sentence below is correct or whether it needs to be revised. Choose the correct option.

Determine whether the underlined portion of the sentence below is correct or whether it needs to be revised. Choose the correct option.

Yesterday I fell down the stairs and then tried to act as I did so on purpose.
A . Yesterday I fell down the stairs and then
B . Yesterday I fell down the stairs, I
C . I fell down the stairs yesterday, I
D . After I fell down the stairs yesterday; I
E . Falling down the stairs; I

Answer: A

Explanation:

“Yesterday I fell down the stairs, I” and “I fell down the stairs yesterday, I” are run-ons. D and E misuse their semicolons: the parts before them are not independent clauses.