Hi @Kim_Hakseon,
Your general options are currently #1 (sequential in-place major version upgrades with minimal downtime) or #3 (use mongodump & mongorestore to try to upgrade directly). You also have to coordinate upgrading your driver(s), which should happen prior to the server upgrade.
There are some variations on the upgrade options if you can get to a version of MongoDB supported by automation tooling. For further discussion, see my reply on Replace mongodb binaries all at once? - #3 by Stennie_X.
Since you are catching up on seven years of upgrades, a lot has changed. If you are following the in-place upgrade approach, make sure you read the upgrade steps and compatibility changes for each major release. Some major releases may have slightly different upgrade steps. In particular, MongoDB 3.4+ major version upgrades include an explicit setFeatureCompatibilityVersion command to enable persisting data changes that previous releases may not not handle gracefully.
Regards,
Stennie