A student needs to enroll for a minimum of 60 credits. A student cannot enroll for more than 70 credits. The credits are divided amongst project and three distinct sets of courses namely, core courses, specialization courses, and elective courses. It is compulsory for a student to enroll for exactly 15 credits of core courses and exactly 20 credits of project. In addition, a student has to enroll for a minimum of 10 credits of specialization courses. The maximum credits of elective courses that a student can enroll for is _______

Let the total enrolled credits be $T$.

According to the problem:

• Total credits allowed: $60 \le T \le 70$

• Project credits: $C_{\text{project}} = 20$

• Core course credits: $C_{\text{core}} = 15$

• Specialization course credits: $C_{\text{spec}} \ge 10$

• Elective course credits: $C_{\text{elect}}$

The total credits enrolled is given by:

To maximize the elective credits $C_{\text{elect}}$, we need to maximize the total credits ($T = 70$) and minimize the specialization credits ($C_{\text{spec}} = 10$):

Thus, the maximum credits of elective courses is 25, which corresponds to option (D).