Statement–Assumption — “If there were posters available of these top IT professionals, they would have replaced Shahrukh and Sachin on many hostel walls by now.” Assumptions: I. Posters of IT professionals are not currently available in the market. II. Top IT professionals are so popular among students that their posters would displace film and sports icons.

Introduction / Context:
The sentence uses a counterfactual: if posters of certain IT stars existed, they would have replaced celebrity posters on hostel walls. We need to identify the hidden beliefs that make this claim reasonable.

Given Data / Assumptions:

• “If there were posters available …” suggests such posters are presently unavailable.
• The claim predicts replacement—i.e., IT icons’ appeal would surpass existing film/sports icons among students.

Concept / Approach:
For a counterfactual of this kind, two things must be true: (a) the missing condition (availability) is what prevents the outcome at present, and (b) the outcome (replacement) would indeed occur given availability, which rests on presumed popularity or aspirational pull.

Step-by-Step Solution:
1) Assumption I: The “if there were” framing ordinarily implies non-availability now; otherwise, availability would not be the barrier. Hence I is implicit.2) Assumption II: Predicting “replacement” requires believing student demand for these posters is strong enough to displace major celebrities. Therefore II is also implicit.

Verification / Alternative check:
Without (I), the counterfactual loses force; without (II), replacement would be an overreach. Both are needed.

Why Other Options Are Wrong:
Only-I/Only-II/Either/Neither each omits part of the logic behind the forecasted displacement.

Common Pitfalls:
Treating “if available” as a mere wish rather than the stated binding constraint, or ignoring the popularity premise required for replacement.

Final Answer:
if both I and II is implicit.