--It was on the very farm ___ we once worked.

A. that B. which

C. what D. where

【答案】D

【解析】考查定语从句。句意：你在哪里学的种花？就在我们曾经工作的农场里。根据句意及句子结构分析可知，此处为定语从句，先行词是the very farm，连词在从句中作地点状语，应使用关系副词。故选D。