which two statements are true about VLAN traffic?

Given the above partial configuration, which two statements are true about VLAN traffic? (Choose two.)

A.
VLANs 1-5 will use fa0/10 as a backup only.

B.
VLANs 6-10 will use fa0/10 as a backup only.

C.
VLANs 1-5 will be blocked if fa0/10 goes down.

D.
VLANs 1-10 are configured to load share between fa0/10 and fa0/12.

E.
VLANs 6-10 have a port priority of 128 on fa0/10.

Explanation:

Spanning-Tree Protocol (STP) is a Layer 2 protocol that utilizes a special-purpose algorithm to discover physical loops in a network and effect a logical loop-free topology. STP creates a loop-free tree structure consisting of leaves and branches that span the entire Layer 2 network. The actual mechanics of how bridges communicate and how the STP algorithm works will be discussed at length in the following topics. Note that the terms bridge and switch are used interchangeably when discussing STP. In addition, unless otherwise indicated, connections between switches are assumed to be trunks.

Load sharing can be accomplished using a couple of methods. The most common method of load sharing is through root bridge placement on a per-VLAN basis. This will distribute traffic for separate VLANs across separate paths to different root bridges. A separate method divides the bandwidth supplied by parallel trunks connecting switches. To avoid loops, STP normally blocks all but one parallel link between switches. Using load sharing, traffic can be divided between the links according to which VLAN the traffic belongs.

Load sharing can be configured on trunk ports by using STP port priorities or STP path costs. For load sharing using STP port priorities, both load-sharing links must be connected to the same switch. For load sharing using STP path costs, each load-sharing link can be connected to the same switch or to two different switches.
Load Sharing Using STP Port Priorities
When two ports on the same switch form a loop, the STP port priority setting determines which port is enabled and which port is in a blocking state. The priorities on a parallel trunk port can be set so that the port carries all the traffic for a given VLAN. The trunk port with the higher priority (lower values) for a VLAN is forwarding traffic for that VLAN. The trunk port with the lower priority (higher values) for the same VLAN remains in a Blocking state for that VLAN. One trunk port sends or receives all traffic for the VLAN.