Explanation:

Here's an explanation of the options:

- Goods: This refers to items that are the subject of a sale, but not all considerations in a contract of sale are "goods." Payment or exchange generally involves something other than goods.

- Movable only: While goods are generally movable, the key consideration in a sale isn't about movability but something else.

- Price: This is the money consideration that forms the essence of a contract of sale. It's what the buyer pays in return for goods or services.

- Purchase: This term refers to the act of buying something, which is an outcome rather than a consideration itself.

Your answer is option:3- price.