Statements : I. All fish are tortoise. II. No tortoise is a crocodile. Inferences : A) No crocodile is a fish. B) No fish is a crocodile. Codes

Both inferences follow, so the answer is C. Start by translating the statements. Statement I, 'All fish are tortoise', puts the fish circle entirely inside the tortoise circle. Statement II, 'No tortoise is a crocodile', means the tortoise circle and the crocodile circle do not overlap at all. Chain them together: every fish is a tortoise, and no tortoise is a crocodile, so no fish can be a crocodile. That makes Inference B valid.

Now Inference A, 'No crocodile is a fish'. A universal negative (E-type) statement converts freely: 'No fish is a crocodile' means exactly the same as 'No crocodile is a fish'. So A is also valid. Both options A and B are wrong for this reason. Options A and B each say only one inference follows, and option D says neither does, so C is the only code that fits.

This is a basic Venn-diagram and syllabus-level reasoning item, the kind that appears in the Logical Reasoning and Analytical Ability section of UPPSC Prelims. The skill matters beyond the exam because clear conditional reasoning is what you need in Mains essays and case studies.

Trap: aspirants see 'No crocodile is a fish' as a new claim and assume it needs separate proof. Check the converse of an E-type statement before rejecting an inference.