What happens to mysql synchronous replication when read replica can't respond?

In the official doc https://dev.mysql.com/doc/mysql-replication-excerpt/8.0/en/replication.html It mentioned that if synchronous replication is required, use NDB instead >For scenarios where synchronous replication is required, use NDB Cluster (see MySQL NDB Cluster 7.5 and NDB Cluster 7.6). **Question 1.** Does mysql not support synchronous replication, only mysql cluster support synchronous replication? **Question 2.** Where is the doc for synchronous replciation for NDB I see multiple post mentioning that NDB replication is synchronous by default https://stackoverflow.com/questions/53149674/can-i-implement-synchronous-and-asynchronous-replication-with-the-mysql-cluster But the official doc only mention asynchronous and semisynchronous replication https://dev.mysql.com/doc/refman/8.0/en/mysql-cluster-replication.html > NDB Cluster supports asynchronous replication, more usually referred to simply as “replication”. This section explains how to set up and manage a configuration in which one group of computers operating as an NDB Cluster replicates to a second computer or group of computers. We assume some familiarity on the part of the reader with standard MySQL replication as discussed elsewhere in this Manual. (See Chapter 19, Replication). **Question 3:** If mysql or NDB supports synchronous replication, do they use 2PC? What happens during network partition, or replica nodes are not available? Does NDB sacrifice availability over consistency? Does NDB do leadership election? This post say it does https://dev.mysql.com/blog-archive/2-phase-commit-in-ndbcluster/ But I can't find documentation on the behavior of the trade off on availability vs consistency during network partition or replica failure?