Concept:After the passive structure “was seen,” the present participle form (verb +
−ing) is used to describe an observed action.
Explanation:The sentence requires a non-finite verb after “was seen.”
The structure “was seen + present participle” means someone was observed while doing the action.
Thus, the correct form is “going,” as in “He was seen going to school.”
The other options are incorrect:
− “went” is the simple past tense.
− “gone” is the past participle form.
− “go” is the base form.
Answer:B. going