Please answer this correctly

Which sentence has an adjective clause? a.mike rode his bike on mountain trails because he found them challenging.b.gary donated to charity whenever he could.c.liz,who could always make people laugh,was loved by the whole block.d.ever since adam was a little boy,he had his father in the fields

Iopened the door quietly,then stood in the doorway rewrite using ..ing participle

6. the two primary purposes for sending business messages are typically to and