The correct answer is 10.

Solution:

Considering the given number pattern.

Here, the numbers are increasing.
So, to find the missing number, we first find the rule.

Note that:
1 + 3 = 4
4 + 3 = 7
7 + 3 = 10
10 + 3 = 13

So, the rule is "add 3".

Then, the missing number is 10.