In the following sentence, four words are underlined out of which one word is misspelt. Identify the INCORRECTLY spelt word.
After the recapture (A) of Tololing and the adjacent features, evacting (B) the enemy from this well-fortified (C) position became a priority. (D)

The correct answer/option is B.

Let us analyze the spelling of each of the underlined words in the given sentence:
1. recapture (A): This is spelled correctly. It means the act of retaking or regaining control of something.
2. evacting (B): This word is misspelt. The correct spelling is evacuating or evicting depending on the exact intended context (here, removing/clearing the enemy from a position refers to "evicting" or "evacuating/clearing"). If the sentence intends to say "removing the enemy from a position", the word should be "evicting" or "clearing/vacating". Looking at the base misspelling "evacting", it is a misspelling of "evicting" (forcing out) or "evacuating". Regardless of the exact intended word, "evacting" is not a valid English word.
3. well-fortified (C): This is spelled correctly. It means provided with defensive works as protection against attack.
4. priority (D): This is spelled correctly. It means the fact or condition of being regarded as more important than others.

Therefore, the incorrectly spelt word is identified by option B.