A[20][10]
to reach A[11][5]
we have to cross 11 rows and each row contains 10(no. of columns) elements and in 12th row we have to cross 5 elements
total elements to cross= $11*10+5=115$
each element occupies 4 words space
total space = $4*115=460$
address of $A[11][5] = base address + space occupied by elements before it$
$=100+460=560$
option (A)