Let p be a proposition concerning an integer n in Z with p meaning ' m o d     2 = 0 nmod2=0'. Which one of the following sets is the correct truth set of p? 1 point { 2 : ∈ } {2 r :r∈Z} { 2 : ∈ } {2r:r∈Z} { 2 : ∈ } {2 r :r∈N} { 2 + 1 : ∈ } {2r+1:r∈Z}