[tex]\huge\fbox{Answer ☘}[/tex]
☆ given that ,
ABCD is a parallelogram
☆ we know that ,
opposite angles of a parallelogram are equal.
Therefore ,
[tex]\bold\blue{∠B \:= \:∠D}[/tex]
[tex]\pink{3x = x + 52} \\ \pink{3x - x = 52 }\\\pink{ 2x = 52 }\\\pink{ x = \frac{52}{2}} \\ \\ \bold\blue{x = 26}[/tex]
therefore , ∠B = 3x = 3 ( 26° ) = 78°
[tex]\fbox{∠B \: = \: 78°}[/tex]
thus option ( A ) is correct ~
hope helpful~
