Concept:When a nested radical repeats infinitely, we can set the entire expression equal to a variable and substitute the inner part with the same variable.Explanation:Let x=12+12+12+....The pattern inside repeats, so x=12+x.Square both sides: x2=12+x.Rearrange: x2−x−12=0.Factor: (x−4)(x+3)=0.Thus, x=4 or x=−3.Since a square root cannot be negative, discard x=−3.Answer:The value is 4. Option B.