Answer:
[tex] \boxed{ \bold{ \huge{ \boxed{ \sf{4 \sqrt{15k} + 3 \sqrt{5k} }}}}}[/tex]
Option B is the correct option.
Step-by-step explanation:
[tex] \sf{ \sqrt{15k} (4 + \sqrt{3} )}[/tex]
Distribute √ 15 k through the parentheses
[tex] \dashrightarrow{ \sf{4 \sqrt{15k} + \sqrt{15k \times 3}}} [/tex]
[tex] \dashrightarrow{ \sf{4 \sqrt{15k} + \sqrt{45k} }}[/tex]
[tex] \dashrightarrow{ \sf{4 \sqrt{15k} + 3 \sqrt{5k} }}[/tex]
Hope I helped!
Best regards! :D