I’m sure Luisa was very disappointed when she failed the exam

Knowledge: Modal verbs

Explain:

Could have Ved/V3: could have done something

May/might + V(infinitive): can, probably do

Must have Ved/V3: must have done something

I’m sure: I’m sure => use “must”

I’m sure Luisa was very disappointed when she failed the exam.

= D. Luisa must have been very disappointed when she failed the exam.

A. Luisa may have been very disappointed when she failed the exam. => wrong in meaning

B. wrong in “may be”

C. wrong in “might be”

Choose EASY