Final answer:
The correct option to fill in the blank is 'c. missed'.
Step-by-step explanation:
The correct option to fill in the blank is:
c. missed
In this sentence, the action of missing the speaker's pets occurred in the past, so the past tense verb 'missed' should be used. The other options are not appropriate in this context. For example, 'will miss' and 'will be missing' indicate future actions, while 'miss' is the base form of the verb and doesn't convey the past tense.
Learn more about Past tense verb