Select the most appropriate option to fill in the blank.
His actions are incompatible ____________ his words.

Correct option is C

The correct option to fill in the blank is (c) with.
Explanation: The fixed prepositional collocation is “compatible/incompatible with.” “Incompatible with” means not consistent or in harmony with (Hindi: असंगत / मेल न खाने वाला). Hence, “His actions are incompatible with his words.”
Example: Their proposals are incompatible with the company’s core values.
Why other options are incorrect:
· (a) to: Used after adjectives like “superior/inferior to,” not with incompatible. (Hindi: को/तक, यहाँ उपयुक्त नहीं)
· (b) for: Suggests purpose/benefit; not the idiomatic pair with incompatible. (Hindi: के लिए)
· (d) by: Indicates agency/instrument; not used after incompatible. (Hindi: द्वारा)