How many products (including stereoisomers) are expected from monochlorination of the following compound?

The compound is $2\text{-methylbutane}$. It has four types of hydrogen atoms available for substitution:Primary H at C1: Yields $1\text{-chloro-2-methylbutane}$. This carbon (C2) becomes chiral. Total: $2$ products ($d+l$).Tertiary H at C2: Yields $2\text{-chloro-2-methylbutane}$. No chiral center. Total: $1$ product.Secondary H at C3: Yields $2\text{-chloro-3-methylbutane}$. C3 becomes chiral. Total: $2$ products ($d+l$).Primary H at C4: Yields $1\text{-chloro-3-methylbutane}$. No chiral center. Total: $1$ product.Total products $=2+1+2+1=6$.