What type of printer heats toner to adhere it to the paper? inkjet . impact. 3d. laser.

laser

Explanation:

These are well known printer types now.  Let's review how they work to determine in which does heat plays a role.

inkjet: inkjet printers are printer throwing ink at the paper in the form of little drops.  No heat involved here.

impact: That's the oldest technology, where a printing head is moving left and right to punch a printing ribbon and transfer ink onto the paper.  No heat involved.

3D: 3D printers don't usually use paper... as they use other materials to create a 3D representation of a model.  Heat is involved in the melting of the material before it's placed on the building model.  But no paper involved here.

laser: laser printers are working very much like a photocopier machine... memorizing the pattern to be printed, then transferring it onto paper... using heat.