The part of the electromagnetic spectrum usually used for communication is

The part of the electromagnetic spectrum usually used for communication is of  radio waves, infrared waves and microwaves.

But most common waves used in communication are radio waves.

this allows people to make the best decision or pursue the best option. when alternatives are weighed using their advantages and disadvantages, the option whose disadvantages outweigh the advantages (based on a qualitative or quantitative analysis) are shunned while those whose advantages outweigh their disadvantages are pursued.  

the assestment will probley apele with cause and effect