Final answer:
The National Constituent Assembly supported a constitutional monarchy, whereas the Jacobins wanted to overthrow the monarchy completely.
Step-by-step explanation:
The group that supported having a king but only in a constitutional monarchy was the National Constituent Assembly. This Assembly was one of the key players during the early stages of the French Revolution, which sought to establish a constitutional monarchy similar to the British system.
On the other hand, the Jacobins were a radical political club that supported overthrowing the monarchy entirely, which contrasts with the goals of the National Constituent Assembly.