Which of the following are examples of forced closed kinematic pairs?
1. Cam and roller mechanism
2. Door closing mechanism
3. Slider-crank mechanism
4. Automotive clutch operating
Mechanism Select the correct answer using the codes given below:
(a) 1, 2 and 4 (b) 1 and 3
(c) 2, 3 and 4 (d) 1, 2, 3 and 4