The word 'while' refers to two actions that happened simultaneously. Hence both will be in past tense.
Option C: 'Disappeared' is a simple past tense verb that states an action that happened in the past 'while I was on holiday'. Hence option C is correct.
Option A: 'Has disappeared' is in present perfect tense and states an action that just happened. It does not agree with the sentence which is set back in time.
Option B: 'Had disappeared' states an action that completed in the past, before another past action took place. The sentence does not present actions one after another, but two at the same time.
Option D: 'Disappears' is a simple present tense and states a daily habit or a present action while it's happening. The sentence though, is in past tense.
Hence options A, B and D are wrong.