Which is correct?

Question $33$ options:

$1)$

Some experts $($Colquitt and Pritchard, $2017)$ have explained how differentiated instruction could be used in high school personal weight training courses.

$2)$

Colquitt & Pritchard $(2017)$ explained how differentiated instruction could be used in high school personal weight training courses.

$3)$

Colquitt and Pritchard explained how differentiated instruction could be used in high school personal weight training courses $(2017).$

$4)$

Colquitt and Pritchard $(2017)$ explained how differentiated instruction could be used in high school personal weight training courses.