Deductions & credits

Should house flipping go under schedule c or d? I flipped a house. I really do not want a letter from the IRS here. 

 

I have a schedule c business for real estate which I've had for years doing other real estate activities. 

 

I also have a w2 job. 

 

I've read both opinions that it should go on schedule c or d. 

 

I received a 1099s for the property form escrow.