Self-induction

[A] is a circuit connected in series with resistor of resistance $R,$ coil of self-inductance $L,$ and power supply of voltage $V$ . If we turn on the switch at $t_0$ and turn it off at $t_2$ , the intensity of the current flowing through the resistor changes with time as in [B]. Which of the following statements is correct?

a) The direction of the current between $t_0$ and $t_1$ is the b direction in [A].

b) The resistance effect of the coil is maximized between $t_1$ and $t_2.$

c) The intensity of internal magnetic field inside the coil is constant between $t_2$ and $t_3.$