Which sentence uses the underlined pronoun correctly?

A.

Grandmother cooked all of our a special dinner last night.

B.

Grandmother cooked all of we a special dinner last night.

C.

Grandmother cooked all of us a special dinner last night.

There's nothing underlined in the question.

But I can tell you that choices 'A' and 'B' are awkward constructs,

which grate on the ear and sound ridiculous.

Choice-C, in contrast, sounds as good and tastes as good as

Grandma's special dinner.