Given a data frame named product with column names $[\text{'}$c$1\text{'},\text{'}$c$2\text{'},\text{'}$c$3\text{'}],$ how to select the columns $\text{'}$c$2\text{'}$ and $\text{'}$c$3\text{'}?$

product $[\text{'}$c$2,\text{'}\text{'}3\text{'}]$

productiloci: $[$c$2$;$\text{'}\text{'}$c$3\text{'}]$

product loc$($i$)(\text{'}$c$2\text{'},\text{'}$c$3\text{'})]$

product.locli, $c2,c3||$