Answer:
option c
Step-by-step explanation:
a) NOT TRUE
A composite number is a positive integer that can be formed by multiplying two smaller positive integers.
3 and 7 are not composite numbers because each of them can only be divided by one and itself
b) NOT TRUE
2 is also a prime number so 3 and 7 are not the only numbers
c) TRUE
All the number listed are prime numbers hence why they are all at the bottom of the tree (only have 1 and itself as factors)
d) NOT TRUE
21 is not a prime number. The number 21 is divisible by 1, 3, 7, 21. For a number to be classified as a prime number, it should have exactly two factors. Since 21 has more than two factors, i.e. 1, 3, 7, 21, it is not a prime number.
