Option A: 'Have worked' is in present perfect tense.
'Have' in 'have worked' is a plural verb whereas the subject 'Mr. Clark' is singular. Hence the subject-verb do not agree in number.
Option B: 'Had worked' is in past perfect tense. It states an action that completed in the past, before another action happened (in the past).
It does not agree to the given sentence in meaning.
Option C: 'Is working' is in present continuous tense. It states an action that is continuing in the present. But the given sentence states a past action 'Then he gave it up'. Hence the sentence is not in present tense.
Hence options A, B and C are wrong.
Option D: 'Worked' is in simple past tense and states an action that happened in the past. It agrees to the given sentence that also is in simple past tense 'gave up'.