Answer: The correct option is (D) 18 : 21.
Step-by-step explanation: We are given to select the ratio that is equivalent to the ratio 24 : 28.
We have
[tex]24:28=\dfrac{24}{28}=\dfrac{6}{7}=6:7.[/tex]
Option (A) : The given ratio is 1 : 4.
We have
[tex]1:4\neq 6:7.[/tex]
So, this option is NOT correct.
Option (B) : The given ratio is 4 : 7.
We have
[tex]4:7\neq 6:7.[/tex]
So, this option is NOT correct.
Option (C) : The given ratio is 12 : 16.
We have
[tex]12:16=\dfrac{12}{16}=\dfrac{3}{4}=3:4\neq6:7.[/tex]
So, this option is NOT correct.
Option (D) : The given ratio is 18 : 21.
We have
[tex]18:21=\dfrac{18}{21}=\dfrac{6}{7}=6:7.[/tex]
So, this option is CORRECT.
Thus, (D) is the correct option.
