Write missing numbers.

The correct answer is: 50, 70, 90

In the question there is a table in which some numbers are missing.
We have to find the missing numbers in the given picture.
Firstly, on counting forward by 10s after 40 we get 50.
Similarly, on counting forward by 10s after 60 we get 70.
Again, on counting forward by 10s after 80 we get 90.
So, the missing numbers are 50, 70, 90.
Therefore, the correct option is a, i.e., 50, 70 and 90.