If the customer core or distribution switch is a Cisco switch, how should the QSFP+ and cables be ordered?

A customer has decided to connect their IDPA Top-of-Rack (ToR) switch using the 40 GbE QSFP+ uplinks.

If the customer core or distribution switch is a Cisco switch, how should the QSFP+ and cables be ordered?
A . QSFP+ for IDPA ToR switch through Dell EMC
QSFP+ for customer switch through Dell EMC
MTP crossover cables through customer vendor or Dell EMC
B . QSFP+ and Twinax uplink cables through Dell EMC
C . 40 GbE-to-40 GbE uplink cables with QSFP+ optics attached through Dell EMC
D . QSFP+ for IDPA ToR switch through Dell EMC
QSFP+ for customer switch through customer vendor
MTP crossover cables through Dell EMC or customer provided

Answer: D