Which of the following are the examples of: discrete variables ?
1. Number of errors per page in. a book.
2. Height of individuals measured in cm.
3. Waiting time to failure of electric bulbs,
4. Number of leaves on branches of a tree.
Select the correct answer using the code given below :

Options

A. 1 only
B. 1 and 4
C. 3 and 4
D. 2 and 4