which of the following is a radical equiations in one variable

A.
[tex] \sqrt{m} = 2[/tex]
B.
[tex] \sqrt{12} = 5[/tex]
C.
[tex]2x \sqrt{5} + 3y \sqrt{3} = 10[/tex]
D.
[tex] \sqrt{12} + \sqrt{30} = 7[/tex]

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