In the pattern given:
if we consider a single figure, each row in that figure has ___ number of squares.
odd
In the pattern above, let's take the first figure
It has one row and there is only 1 square in it.
In the second figure, it has 1 square in its first row and 3 squares in its second row.
Hence, in each figure, the number of squares in each row is an odd number. It's not any odd number. It is the odd number in a sequential order, starting from 1.