Final answer:
According to Cisco's OSPF routing protocol, the formula for calculating the cost of a link is 10^8 divided by the bandwidth in bits per second. For a 100 Mbps link, the calculated cost is 1. However, in practice, Cisco's default assigned cost for a 100 Mbps link is typically rounded to 10, which isn't an option provided in the question.
Step-by-step explanation:
The question pertains to Cisco's Open Shortest Path First (OSPF) routing protocol and its default costs for network links. In OSPF, the default cost of a link is inversely proportional to its bandwidth, meaning the higher the bandwidth, the lower the cost. According to Cisco, the formula to calculate the cost is 10^8 divided by the bandwidth in bits per second. Therefore, for a link with a bandwidth of 100 Mbps (100,000,000 bps), the default cost can be found by calculating 10^8 / 100,000,000, which equals 1. However, if we look at predefined cost values for OSPF (which often round the cost for easier readability), a bandwidth of 100 Mbps may be assigned a default cost of 10, which is the rounded assigned cost of a 100 Mbps link in Cisco's OSPF implementation, despite it not being one of the provided multiple choice answers.