The correct option is C depository
The word that has same meaning as the italicized word in both sentences is option C, depository. Depository means a warehouse where things are stored or cache. The context of first sentence is that Literature is a warehouse where weapons of wit and irony are stored. Second sentence means all vital and strength-giving things are in the youth of today. Option A 'collection' means gathering. Option B 'godown' means is a storage place where huge things are stored before they are sold. Option D 'heap' means pile pr stack. So, the options A, B and D are incorrect to be used in both the sentences together. The correct answer is option C, depository.