A $46-$year$-$old man is currently enrolled in a Phase $2$ study of a drug for severe diabetic neuropathy. While the study is on$-$going, a new drug becomes commercially available that may have equal or greater benefit to the subject. The investigator should do which of the following?

Give the subject comprehensive infingrmation about the new drug, including its side effects. Discuss the pros and cons of both the investigational drug and the commercially available drug and then allow the subject to decide whether to withdraw from the research to take the new drug.

Tell the subject about the new drug but discourage him from switching treatments until the study is completed.

Withhold this new information to avoid confusing the subject with other treatment options or alternatives.

Do not tell the subject about the new drug because physicians have the right to try out new treatments with their patients.