Answer:
A. laid
Step-by-step explanation:
Lain and laint are both past participle of lie, and lie is used to be or put yourself down in a flat position, so by process of elimination, it's not C and D.
Laid and layed: what's the difference
Laid is the standard way of saying the past participle of lie,
but layed is the archaic way of the past participle, so it wouldn't work in modern grammar.
"The buried treasure had laid there for centuries."
The answer is:
A) laid