What was the reason Qatar had faced almost 3 years of diplomatic cut-offs from the rest of the Gulf Countries?

1. Qatar was accused of supporting terrorist groups
2. It supported Iran
3. It supported the US against Iraq
4. Both a & b

The Qatar diplomatic crisis was a diplomatic incident that began on 5 June 2017 when Saudi Arabia, the United Arab Emirates, Bahrain, and Egypt severed diplomatic relations with Qatar and banned Qatar-registered planes and ships from utilizing their airspace and sea routes, along with side Saudi Arabia blocking Qatar’s only land crossing.