Can somebody explain the DD Form 2656-5 (Reserve Component Survivor Benefits Plan) and best option?

Also without that plan in the event of Your death Your survivors will get some of their other entitlements but not any of Your retired pay unless You select an option to do so. They still will only get a percentage, less than half of what You receive bu that sure better than leaving them with nothing. If However You outlive them all then it would not apply and would not pass on. Make sure You check on this, many have found it isn't explained very well and it sure is important.

It provides for your dependents in case of youreally death as long as they are under 18 or 21 if in school. They only take 3% of your retired pay to fund it.

It is your survivors portion of your retirement pay to provide in addition to life insurance when you pass. If you choose to elect to not take the spousal option, you must have your spouse sign in agreement. If you are divorced and you were married for over the XX years required, you will also have to have them sign approval of declining the spousal election. Go talk to your personnel section and JAG office about this to get the correct information for your situation. You can also go to the Air Force's legal assistance website (don't need a CAC or .mil computer to log on to it), it has links to the closed military legal office (any branch) and links to topics regarding this and many other legal questions we have as military members.