CSIR UGC NET June 2019 Part B Question 30

Question

What is the rank of the following matrix?

$$\begin{pmatrix}1 & 1 & 1 & 1 & 1 \\ 1 & 2 & 2 & 2 & 2 \\ 1 & 2 & 3 & 3 & 3 \\ 1 & 2 & 3 & 4 & 4 \\ 1 & 2 & 3 & 4 & 5 \end{pmatrix}$$

1. 2

2. 3

3. 4

4. 5