Randy, an avid hunter, wishes to build a hunting cabin for himself and his companion to use during hunting season. He travelled around the area and found a farm that had an ideal piece of land. Randy telephoned the farmer and asked to meet him over coffee. Bob, the farmer, decided to sell Randy the lot for $3,000. Randy agreed, handing Bob $500 in cash as a deposit. When Randy arrived for hunting season three months later, having erected a cabin in the summer, he offered Bob another $1,000 towards the purchase price. However, he found quite a surprise. Bob decided he no longer wishes to sell the land and informs Randy he will have to tear down his building. Bob tells Randy that he may do it because they did not have a written agreement.

a. Apply the four criteria of the "doctrine of part performance" to the circumstances and explain their relevance to both Randy's arguments and Bob's defence.

CONSIDER ONLY CANADIAN LAWS TO ANSWER THIS QUESTION.