△ABC 中,∠A是锐角,且sin2A = sin(π/3 + B)sin(π/3 - B) + sin2B,且a = √3,则b2 + c2 的取值范围是?
A、(3,6]
B、[3,6]
C、(4,6]
D、[4,6]
E、(5,6]
F、[5,6]