Correct option is A
Concept Used:
A prime number is a number which is only divisible by itself
Solution:
The smallest 5-digit number is 10000
We can check options for prime number one by one:
10001 is divisible by 73.
10003 is divisible by 7.
10007 is not divisible by any number except itself.
Hence 10007 is the smallest 5-digit prime number
Although 10009 is also a prime number but 10007 is smallest.
Thus, option (A) 10007 is correct.