How does Traceroute map the route that a packet travels from point A to point B?

A.
It uses a TCP Timestamp packet that will elicit a time exceed in transit message.

B.
It uses a protocol that will be rejected at the gateways on its way to its destination.

C.
It manipulates the value of time to live (TTL) parameter packet to elicit a time exceeded in transit message.

D.
It manipulated flags within packets to force gateways into generating error messages.

Explanation:
Traceroute works by increasing the "time-to-live" value of each successive batch of packets sent. The first three packets have a time-to-live (TTL) value of one (implying that they make a single hop). The next three packets have a TTL value of 2, and so on. When a packet passes through a host, normally the host decrements the TTL value by one, and forwards the packet to the next host. When a packet with a TTL of one reaches a host, the host discards the packet and sends an ICMP time exceeded (type 11) packet to the sender. The traceroute utility uses these returning packets to produce a list of hosts that the packets have traversed en route to the destination.