Complete the Partial Definition of a Contingent Liability Using the Options

Complete the partial definition of a contingent liability using the options a to f below:
a. able to be measured reliably
b. current
c. improbable future events
d. possible
e. uncertain future events
f. within the control of the entity
-A ________________ obligation that arises from past events and whose existence will be confirmed only by the occurrence of one or more ________________ not wholly ________________.