The correct option is B Attractive
The words 'repellent' refers to being repulsive and causing disgust or distaste.
Option A, troublesome refers to something causing difficulty or annoyance.
Option B, attractive refers to something pleasing or appealing to the senses.
Option C, thing refers to an action, event, thought or utterance.
Option D, hostile refers to showing or feeling opposition or dislike.
Thus, according to the meaning, the word 'attractive' is the farthest in meaning from the word 'repellent'.