Answer:
C 4:1
D 24:6
F 1200:300
Explanation:
The given ratio is

Simplify
Divide by 3 both numerator and denominator

Verify each case
case A) we have

Compare with the given ratio

therefore
The ratio is not equivalent
case B) we have

Compare with the given ratio

therefore
The ratio is not equivalent
case C) we have

Compare with the given ratio

therefore
The ratio is equivalent
case D) we have

Simplify
Divide by 6 both numerator and denominator

Compare with the given ratio

therefore
The ratio is equivalent
case E) we have

Simplify
Divide by 3 both numerator and denominator

Compare with the given ratio

therefore
The ratio is not equivalent
case F) we have

Simplify
Divide by 300 both numerator and denominator

Compare with the given ratio

therefore
The ratio is equivalent
case G) we have
----> irreducible
Compare with the given ratio

therefore
The ratio is not equivalent