Choose the correct alternative to complete the series: $a . c a . b e . b c c . . . b c a$

To answer these questions study carefully the following arrangement of letters, digits and symbols.

$6,=,\$, C,E, 3,8 ,G,L,M, 7, \star, @ ,P,R, 4, \# ,N,T, 5, S,V$

If all the symbols in the arrangement are removed, then which of the following will be the $7^{th}$ to the left of the $13^{th}$ element from the left end?

To answer these questions, study the following arrangement of digits, letters and symbols carefully.

$6, N,P ,=,@, 7,1 ,\&, R, T, 3, L, ,B, \star, E ,4,\# , 8, G,H ,\$, 5, K,M ,?, 2, D,C$

How many such digits are there in the arrangement each of which is immediately followed by a symbol but not immediately preceded by a letter?