Question

He is so old___ he cannot walk (a) so (b) that (c) if (d) but​

Answer 1

Answer:

(b) that

He is so old that he cannot walk.

Explanation:

$\rightarrow$ We are dealing with conjunctions here.

$\rightarrow$ Conjunctions are the words used to connect two or more sentences as one.

$\rightarrow$ They are also called connectors.

Answer 2

Answer:

that

Explanation:

as if you place option (a) the sentence will be inappropriate and similarly option (c)and (d) will also be wrong hence option (b) that is answer

hope it might help you