No, column B needs to be completed, use the app here to find column B

https://www.healthcare.gov/tax-tool/#/

To clarify: the issue is the affordability and you (our your taxpayer client) need to look up, for their circumstances, location, family, etc, what the "Monthly second lowest cost silver plan (SLCSP) premium" is for them, and use that on the tax return. Col C means they did not file for advanced premium credits. Col B will be used to determine if they qualify for it on the tax return, now.