P sold his car to D "provided that the car is road worthy." D did not pay P. At trial there is conflicting evidence as to whether the car was road worthy. Who has the burdern of proof on this issue?

P, because a plaintiff always bears the burden of proof

or

D, regardless of whether the condition that the car is road worthy is construed as a condition subsequent or condition precedent

or

P, if the condition that the car is road worthy is construed as a condition subsequent.

or

D, if the condition that the car is road worthy is construed as a condition subsequent.