سوال ۵۳ کنکور ارشد مدیریت کسب‌وکار (MBA) ۱۴۰۵

Answer: option 1 — must have. Must have + past participle expresses a strong deduction about the past (استنباط قوی دربارهٔ گذشته). The evidence is the team's best performance so far; the speaker infers that it must have put in more effort. The past participle of put is also put.

• 1) must have: correctly links the observed result to an inferred earlier effort.
• 2) should have: is grammatical with put, but normally expresses an earlier duty, criticism, or expectation. The sentence uses the excellent result as evidence for a deduction, rather than recommending effort that may not have occurred.
• 3) will have to be: produces will have to be put in more effort. The passive form wrongly makes the team the recipient of put, rather than the agent making the effort.
• 4) will have been: likewise produces the passive will have been put in more effort and cannot express the team's active effort.

Exam trick: Evidence of a past action points to must have + past participle; an unfulfilled past obligation usually points to should have + past participle.