Canning Club Pop Quiz!

So, at this month's canning club meeting, I had to take a pop quiz!   Heaven, help me! 
There were 30 questions in all.  A quick look around the room, and I was quickly intimidated.  The other test takers had lots more, um, experience than I did.  I felt my palms getting sweaty.

As we checked our work (thankfully, we didn't trade-n-grade!), I was pleased to discover that I'd scored a 27/30.  Hey, that's an A!  Of course, the teacher in me couldn't resist the temptation to tally my score and record it at the top of the page.  :)

Here are 5 things I was pretty proud of myself for knowing:
1.  The plastic lids now available for home canning have not been approved by the USDA.
2.  Foods having a pH value of 4.6 or higher must be canned in a pressure canner.
3.  Zinc lids and bail-type jars are not recommended for home canning.
4.  Using the "hot pack" method when filling jars should prevent fruit from floating to the top of the jar.
5.  Soak jars in a solution of 1 c. vinegar/1 gallon water to remove scale and hard water build-up.

Here are the three questions that I missed:

1.  The spores of Clostridium botulinum can be destroyed by canning the food at a temperature of ___ or above for a specified period of time. 
a. 230 F
b. 240 F
c. 225 F
d. none of the above

2.  Of the food preservation methods we use today, which is the oldest used by man?
a. pickling
b. drying
c. canning
d. fermentation

3.  Why should cream style corn only be canned in pint jars?
a.  the denseness of the canned product
b. This is the size most commonly used.
c. It is difficult to properly cook a larger amount.
d. Air bubbles are more difficult to remove from larger jars.

Think you know the answers (without Googling them -- come on, why cheat on something like this?)?  I'll post the answers tomorrow, so comment now with your guesses if you'd like bragging rights!