Consider a general bidirectional, connected, synchronous network $G=(V,E)$ on $n$ proces$-$

sors. The processors $u_i$ know in advance in a distributed way $($through parent ${?}_i$ and children ${?}_i$

variables$)$ a spanning tree $T=(V,E^{\text{'}})$ of the network, rooted at a designated root processor

$u_0.$ The processors do not have any other knowledge about the network.

Problem $($Counting$).$ Processor $u_0$ eventually terminates knowing $n.$

What would you use to best solve this problem?

A$.$ Convergecast

B$.$ Broadcast

C$.$ Convergecast and Broadcast

D$.$ MaxBFS

E$.$ Cannot be solved as there are no ids