He saw a mouse RUN/RAN across the lounge

Hi!

I read the following grammar question in a TOEIC BOOK:

“112. The assistant jumped up on a chair and screamed when he saw a mouse ______ across the lounge.



A. ran

B. run

C. runs

D. had run



(Answer: B) ((p. 356, LONGMAN PREPARATION SERIES FOR THE NEW TOEIC TEST - Intermediate Course, Fourth Edition, by Lin Lougheed))”



I have two questions.



Question #1:

Do you agree with the above TOEIC book that B is the ONLY correct answer (for the above question)?

I analyzed the original question sentence into the following two types.

Type X1 – … he saw a mouse [OBJECT] run [OBJECTIVE COMPLEMENT] …

Type Y1 - … he saw (that) a mouse [SUBJECT] ran [VERB] …

Considering Type Y1, isn’t A also possible? (If it isn’t possible, would you please let me know the REASON?)



Question #2:

What if there were following choices for the above question?

E. running

F. was running

I analyzed the original question sentence into the following two types.

Type X2 – … he saw a mouse [OBJECT] running [OBJECTIVE COMPLEMENT] …

Type Y2 - … he saw (that) a mouse [SUBJECT] was running [VERB] …

Considering Type X2 and Y2, aren’t E and F also possible? (If they aren’t possible, would you please let me know the REASON?)



Thanks in advance.