I think the easiest way is the function 'Indirect'
=INDIRECT(A1&"!B3",TRUE)
If cell A1 is 'Internet' (w/o the quotes) then this will return the
value in cell B3 on that sheet.
To get the name in A1 you can use
=CHOOSE(A2,"Store","Food","Internet")
with A2 being the cell you linked to the option buttons

DQ