Directions: From each set of sentences given below in question 1 to 10, choose the sentence that is grammatically correct.

A

As soon as I boarded the train, I realized that I left my wallet at home.

B

As soon as I boarded the train, I realize that I had left wallet at home.

C

As soon as I board the train, I realized that I leave my wallet at home.

D

As soon as I boarded the train, I realized that I had left my wallet at home.