Four words have been given out of which three are alike in some manner, while the fourth one is different. Select the odd one.​​

Logic; The logic is specific time units.

Century – A time period of 100 years

Year – A time period of 12 months

Decade – A time period of 10 years

Time – A general concept, not a specific unit

So, Century, Year, and Decade are specific time units, whereas Time is a broad term that does not define a fixed duration.

Thus, the correct option is: (a) Time