Match Pascal library functions to acceptable argument types or domains: (A) ROUND X, (B) ABS X, (C) SQR X, (D) SIN X — with: (1) X in radians, (2) X real, (3) X real or integer.

Introduction / Context:Classic Pascal provides standard functions with defined argument types. Knowing which functions accept integers, reals, or require angular input in radians is a common programming-language fundamentals topic.

Given Data / Assumptions:

• ROUND(X) converts a real to the nearest integer.
• ABS(X) returns absolute value; works for integer and real overloads.
• SQR(X) returns the square; works for integer and real overloads.
• SIN(X) expects an angle in radians.

Concept / Approach:Check each function's signature in standard Pascal (e.g., Turbo Pascal, ISO Pascal) and match to the most general argument category presented in the options.

Step-by-Step Solution:

Verification / Alternative check:In many Pascal dialects: 'ROUND: real → integer; ABS: same type out; SQR: same type out; SIN: real in radians → real.' Example: SIN(pi/2) = 1.0 when X is in radians.

Why Other Options Are Wrong:

• A-2, B-3, C-1, D-3: Assigns SQR to radians and makes SIN accept integer/real nonsensically.
• A-3, B-2, C-2, D-1: Claims ROUND accepts integer, which defeats its purpose.
• A-2, B-3, C-2, D-1: Narrows SQR to reals only; it also works for integers.

Common Pitfalls:

• Feeding degrees into SIN without converting to radians.
• Expecting ROUND to accept integers (it is for rounding reals).

Final Answer:A-2, B-3, C-3, D-1