Is it permissible to combine two prayers while shortening one of them but not the other during travel?

It is permissible for a traveler to combine Dhuhr and Asr prayers, and Maghrib and Isha prayers, at the time of one of them, according to the majority of scholars. As for shortening (Qasr) or performing the full prayer (Itmam), the traveler has a choice between them according to Malik, Shafi'i, Ahmad, and Awza'i, while others, like Thawri and Abu Hanifa, made it obligatory. Shortening the prayer is preferable according to those who permit both options.