The core point of this question is to understand the phrasal verb 'take...into account' which means to consider something. The correct answer is 'account', which can be replaced by 'consider'. Option A is incorrect because 'extend' means to increase or make longer, not related to considering. Option B is incorrect because 'appreciation' refers to gratitude or recognition, not an action of considering. Option C is incorrect because 'take' is part of the phrasal verb but cannot be replaced by 'consider' as they serve different grammatical functions.