In a MapReduce job with 500 map tasks, how many map task attempts will there be?

A.
At least 500.

B.
Exactly 500.

C.
At most 500.

D.
Between 500 and 1000.

E.
It depends on the number of reducers in the job.

Explanation:
From Cloudera Training Course:
Task attempt is a particular instance of an attempt to execute a task
– There will be at least as many task attempts as there are tasks
– If a task attempt fails, another will be started by the JobTracker
– Speculative execution can also result in more task attempts than completed tasks