The answer to your question is 2/4 which is 1/2
The HCF is the Highest Common Factor of a number in this case 54. This is the highest number times another number which = 54. The HCF for 54 is 18.
There you go? Is that right or no?
If I'm right it could be C. IF I'M RIGHT, I'm not totally sure but I hope this helps.