If a radio station holds an online contest in which you must log in to its website and submit personal details such as name, phone number, and e-mail in order to participate, the radio station is:

Offering an exchange

Explanation:

Offering an exchange means that the firm or business is offering something by exchanging something against the same from the person or an individual.

So, in this case, the radio station, held a online contest. in which the person will have to log in to website and fill the personal details like email address, name and phone number.

Therefore, in order to participate the person need to fill their personal details, which is termed as offering an exchange.