Hydrocarbon Doubt

https://preview.redd.it/bief5zs89y6g1.png?width=1440&format=png&auto=webp&s=e8e60268577ee5af5048485923cb15947dff39c0

https://preview.redd.it/zoi4inr89y6g1.png?width=1440&format=png&auto=webp&s=ea6770732132f4f1b5c5e01b59d82bd6ea17a0f8

Question mai KMnO4 at 0°C Syn diol lagata hai na and then CrO3 se Oxidation.. But iska answer B diya and explanation bhi kuch samjh nhi aaya...