here is what I found out

About Labor Certification
on DOL website, it states

"A permanent labor certification issued by the Department of Labor (DOL) allows an employer to hire a foreign worker to work permanently in the United States. In most instances, before the U.S. employer can an immigration petition to the Department of Homeland Security's U.S. Citizenship and Immigration Services (USCIS), "

so I guess this implies that LC is just a certificate, not a immigration petition.

About 140/485
which one is immigrant petition I-140 or I-485?. My I-485 has not been filed. In this case should I answer Yes or No?

---- I-140 is immigration petition, since it is at this time that an employer actually files for immigration of the employee. Extract from USCIS.gov as given below for the purpose of form

"To petition for an alien worker to become a permanent resident in the United States. This form is filed on behalf of an alien, and not by the alien"

485 is clearly an immigration petition.