Which one of the following is not an attractive way to reduce costs and help a company achieve a competitive advantage based on lower overall costs per pair sold than rival companies?

Investing in production improvement option A that reduces reject rates by $50\%$

Delivering orders to footwear retailers in $4$ weeks and not offering mail$-$in rebates

Not offering free shipping to online buyers

Avoiding bidding for endorsement contracts with celebrities$--$celebrity endorsement contracts always raise costs per branded pair sold $($however$,$ stiff competition from rivals may require having at least one celebrity endorsement$)$

Spending a maximum of $$1$ million annually per region on search engine advertising