Help understanding Question MAXPR

Does the Question say that the sub sequence s[1],s[2], .....,s[k] be the continuous elements of array a, but not randomly picked elements in an ascending order.

For example

Let A= { 1,2,3,4,5,6,7,8}

then

Sub sequence possible can be S={ 2,3,4,5} But S={ 2,4,7 } is NOT possible.

just confused about sub sequence, cleared about the AP. Thanks