zooeysfranny Wrote:I still don't quite understand how the argument depends on "other means of cross checks" could you please explain? I understand why the others are wrong but not really why D is right.
The correct answer is E for this question. It may have a been a typo on your part.
This is a most strongly supported question. So, we want to hunt for an answer choice that we can prove (or close) from the text.
The stimulus informs us that older planes had a control panel design that allowed for any changes made by one crew member to be seen immediately by another.
These newer planes make it more difficult to observe these changes in the control panel. I will quote, "Thereby, eliminating a routine means for performing valuable cross-checks."
A consequence of this is that the crew members must verbally inform each other more frequently of changes made.
So, let us think about what this is telling us. On the newer planes, a form of cross-checking involves verbal interaction more so than it did in the older planes. The reason is the control panel design.
Lets look through the answer choices. It is common on these question stems that the answer choices will go too far.
A) We were not given information about length of time in changing of flight controls.
B) Most valuable? Too far. Also the word frequent goes too far. We were informed that the newer flights did an action more frequently, which does not imply frequent.
C) No need? Too far. We know that on older planes, a routine cross-check could be done by looking at the control panel. That doesn't prevent the crew from talking in other ways.
D) Cannot observe? Too far. We know that it is harder to observe on the newer planes, but to say it cannot be is too far.
E) This is provable. How often the crew shares information verbally depends in part on what other means for performing cross-checks are available to the crew members.
First, I like how this answer choice says "depends in part." It does not say large part.
Second, lets look at it in this way.
Older Planes:
Changes can be observed immediately on Control Panel
Newer Planes:
More difficult to observe changes on Control Panel, have to do so verbally more frequently than before.
---This eliminated a routine way of performing cross-checks
So, we know that number of times the crew share information verbally is subject to change. In this case, the newer planes involved MORE of this verbal sharing since one way of doing the cross-checks (viewing on the control panel) was eliminated.