Tarapur Atomic Power Station (TAPS) facts, clarified: Which combination of statements about TAPS, India, is correct? (Choose the option that makes exactly one correct overall choice.)

Introduction / Context:
Exam questions sometimes condense complex facility histories into short statements. Tarapur Atomic Power Station (TAPS) has multiple units across different generations. This item tests factual recall while avoiding the trap of an overstated capacity figure often seen in older summaries.

Given Data / Assumptions:

• We focus on the original TAPS Units 1 and 2 (BWRs) and their historical milestones.
• We need a combination that is factually consistent without introducing multiple correct options.

Concept / Approach:
Historically, TAPS-1 and TAPS-2 are boiling water reactors (BWRs) supplied under U.S. collaboration. They are widely cited as India's first commercial nuclear power reactors, with first criticality occurring in 1969. The commonly quoted initial net capacity for these two units was about 2 × 160 MW ≈ 320 MW, not 400 MW. Hence, a capacity claim of 400 MW for Units 1 and 2 is inaccurate for the historical context.

Step-by-Step Solution:
Evaluate (a): Correct — two American-design BWRs.Evaluate (b): Incorrect — early capacity ≈ 320 MW for Units 1 and 2, not 400 MW.Evaluate (c): Correct — India's first power reactor site with first criticality in 1969.Therefore, the unique correct option is the combined statement: (a) and (c) only.

Verification / Alternative check:
Historical records list TAPS-1 and TAPS-2 as early BWRs with first criticality in 1969; capacity figures around 160 MW per unit are standard in reference texts.

Why Other Options Are Wrong:
(a) alone and (c) alone would give multiple correct options; the question requires a single combined choice. (b) is factually incorrect for the original pair. The combined option in (d) resolves the ambiguity precisely.

Common Pitfalls:

• Memorizing rounded capacities (e.g., “~400 MW”) without checking unit-wise ratings.
• Confusing later TAPS Units 3 and 4 (540 MW PHWRs) with the original BWR units.

Final Answer:
Statements (a) and (c) only are correct.