Partners' correct date of hire?

Three partners get together and form a business.  They start meeting and discussing the business in April 2020, they start working on organizing the business, writing a business plan, researching customers and suppliers, etc in June 2020.  In September 2020 they engage an attorney to create an operating agreement and form an LLC, which is registered with the state in November 2020.   In November and December 2020 they interview and hire employees to start working in January.  They "officially" begin operations in January 2021. 

For purposes of plan eligibility, what is the partners' date of hire?   Under DOL regs it is typically the date an employee first performs an hour of service for the employer for which the employee is entitle to payment.   The partners clearly started working on this in April of 2020, they clearly expect to earn a profit, but they didn't have a formal employer entity until November.   

A.  April 2020
B.  June 2020
C.  November 2020
D.  January 2021
E.  Other________________________

Thanks. 

A

Thanks Mike, A is my opinion too. 

I vote A as well.

Thanks Luke!