Which option is correct ? { please help }

<Q> The main reason that the Earth experiences highest temperatures in the sub-Tropics in the Northern Hemisphere rather than at the Equator is :
(a) Subtropical areas tend to have less cloud cover than equatorial areas .
(b) Subtropical areas have longer day hours in the summer than the
equatorial .
(c) Subtropical areas have an enhanced " Greenhouse effect " compared to equatorial areas .
(d) Subtropical areas are nearer to the oceanic areas than the equatorial locations .​