factor or cause

[jasonlulu_2000]

One of the many ________ leading to widespread unemployment is the growth of mechanization.
A. reasons B. causes C. factors

Are there differences between them?

I think B and C are the same.

Or this is just a fixed phrase.

Want a native to confirm or explain.

Thanks for your help!

Jason

 

[5jj]

There may be causes of unemployment, reasons for it or factors leading to it.

 

[Tdol]

What would you normally put after cause?

 

[5jj]

What would you normally put after cause?

cause for concern, complaint
cause of unemployment, accidents,