How does the sign of the phase angle ϕ, by which the supply voltage leads the current in an L-C-R series circuit, change as the supply frequency is gradually increased from very low to very high values.

Hint: The phase angle depends on the reactance of the circuit.
tanϕ=XL-XCR=2πνL-12πνCR
tanϕ<0(forν<ν0)
tanϕ>0(forν>ν0)
tanϕ=0forν=ν0=12π2C