Consider the following statements for phase-lead compensation:

1. Phase-lead compensation shifts the gain crossover frequency to the right.

2. The maximum phase-lead angle occurs at the arithmetic mean of the corner-frequencies of the phase-lead network.

3. Phase-lead compensation is effective when the slope of the uncompensated system near the gain crossover is low.

Which of the statements given above are correct?
(a) 1, 2 and 3
(b) 1 and 2
(c) 2 and 3
(d) 1 and 3.