Explanation:

AND Gate:
An AND gate is a digital logic gate that has two or more inputs and produces an output that is the logical conjunction of the inputs. In other words, the output of an AND gate is high (or 1) only when all of its inputs are high (or 1).

Inputs and Outputs:
In this case, we have a 3-input AND gate with inputs A, B, and C. The output of the gate will be high (or 1) only when all three inputs are high (or 1).

Options:
Let's go through each option one by one and determine the output of the AND gate for each case.

a) A = 1, B = 1, C = 0:
In this case, two of the inputs (A and B) are high (or 1), but one input (C) is low (or 0). Since all three inputs need to be high for the output to be high, the output of the AND gate will be low (or 0) for this case.

b) A = 1, B = 0, C = 1:
Similar to the previous case, two of the inputs (A and C) are high (or 1), but one input (B) is low (or 0). Therefore, the output of the AND gate will be low (or 0) for this case as well.

c) A = 0, B = 0, C = 0:
In this case, all three inputs (A, B, and C) are low (or 0). Since all three inputs need to be high for the output to be high, the output of the AND gate will be low (or 0) for this case.

d) A = 1, B = 1, C = 1:
This is the only option where all three inputs (A, B, and C) are high (or 1). Therefore, the output of the AND gate will be high (or 1) for this case.

Conclusion:
Based on the conditions of the AND gate, the output will be high (or 1) only when all three inputs (A, B, and C) are high (or 1). Among the given options, only option (d) satisfies this condition. Therefore, the correct answer is option (d).