Let
A (0,-2) B (1,-3) C (2,-4) D ( 3,-5) E (4,-6)
using a graph tool
see the attached figure N 1
case a) exponential

see the attached figure N 2
case b) quadratic

see the attached figure N 3
case c) linear

see the attached figure N 4
case d) linear

see the attached figure N 5
therefore
the answer is
the case c) linear
