Multiple choice:
the continents are light in color because they contain:
a. silicon and aluminum
b. iron and nickel
c. iron and quartz
d. silicon and magnesium

The continents are light in color because they contain:

( A ) silicon and aluminum

Explanation:

Continental crust  -

Continental crust contains more light-colored rocks than oceanic crust .

The continents crust are light in color because they contain:

silicon and aluminum but in the oceanic crust silicon and aluminium not present.

In oceanic crust only silicon and magnesium is present , which is responsible for the dark crust of ocean.

Hence,

Correct option is - ( A ) silicon and aluminum