IS GLOBAL DEVELOPMENTAL DELAY IS RELATED TO LD?

A person with a global developmental delay has more problems learning academic skills than a person with just a learning disability.

Depends on what country you are in though; in the UK “learning disability” has a more global meaning (they use “learning difficulties” where we would say “specific learning disability”).
If you’re this side of the pond though, LD’s are specific, not global. (If it’s an essay question you may want to go to your textbook and do some reading.)