Great emphasis has to be ____________ on the building of our student’s character.

Great emphasis has to be laid on the building of our student’s character.

It is a declarative sentence and the irregular verb 'to be' is used. Therefore, 'laid' is the correct answer. 'Lain' is not correct as it refers to going into a resting position. 'Lied' does not fit in the context. 'Layed' is a misspelt word.