Ticketed At 139 In A 100 Zone

got a ticket at 139 in a 100 zone

I contend that my speeding was around 125 km/hr not 139.

Officer was following me and admitted to me that i did slow down and that i should use my cruise control to maintain my speed.

I want to select option 3 (notice of intention to appear in court)

should i "appear in court with a please of not guity"

and also

should i "intend to challenge the OPP officers evidence" therefore requesting he show up?

THanks