Figure 14.7 shows the transfer characteristics of a base biased CE transistor. Which of the following statements are true?
(a) At Vi = 0.4V, transistor is in active state.
(b) At Vi = 1V , it can be used as an amplifier.
(c) At Vi = 0..5V, it can be used as a switch turned off.
(d) At Vi = 2.5V, it can be used as a switch turned on.