Identify the pair of letters that will replace to form a meaningful word.
ST_ _Y ​​

Given: ST_ _Y ​​

Now, we check each options.

Option (a): AI = STAIY → not a word.

Option (b): AR = STARY → not a word.

Option (c): OR = STORY → STORY — meaningful.

Option (d): AL = STALY → not a word.

So, the correct pair is: STORY.

Thus, correct option is (c).