Which statement about first degree price discrimination is true?

This is exactly the definition of first degree price discrimination discussed in the lecture.

This is true. Since the firm can charge customers exactly their willingness to pay (the maximum amount a customer is prepared to pay) the profit can increase compared to a situation in which the firm does not know the willingness to pay.

This is true. Since the firm perfectly knows the specific willingnesses to pay it can set different prices for different customers.

This is right. In some industries prices are set individually in the form of negotiations (e.g. only a few customers exist in the market). Within such negotiations the firm can try to elicit the customer’s willingness to pay (which is necessary for first degree price discrimination).