If #V# be the velocity with which the football is kicked, then
#K=1/2mV^2#
At highest point, #y-# component of velocity becomes zero, however, #x-# component remains constant. Therefore, kinetic energy, at highest point, is determined by #x-# component of velocity #V#. Let #V_x# and #K'# represent #x-# component of velocity and kinetic energy at highest point respectively.
#V_x=Vcos45=V/sqrt2#
Now, #K'=1/2mV_x^2=1/2m(V/sqrt2)^2=1/2mV^2/2=1/2(1/2mV^2)=1/2K=K/2#
Hence, option #(1)# is correct.