If D is distance between centres of two parallel tracks of gauge G with entire curved leads and equal angles of crossing, total length of crossover, is

If D is distance between centres of two parallel tracks of gauge G wit

1.	If D is distance between centres of two parallel tracks of gauge G with entire curved leads and equal angles of crossing, total length of crossover, is
A.	<span class="root">D (4R - 2G - D)</span>
B.	<span class="root">D (3R - 2G -D)</span>
C.	<span class="root">D (3R + 2G - D) </span>
D.	<span class="root">D (4 + 2G - D)</span>
Answer» B. <span class="root">D (3R - 2G -D)</span>