Question

Which would be a good activity to
develop a child's aesthetic awarness?

a field trip to an arboretum
or
a field trip to a factory

Wouldn't it be a field trip to an
arboretum to see all the woody plants
for scientific and educational purposes?

I suspect this question was crafted by someone who has a particular view of what is beautiful.
I for one, think orchids (in bloom) are astonishingly beautiful, but also, see beauty in a giant numerically controlled punch press making parts for large engines.

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Your "correct" answer is one, however, there are students who will see the beauty in engineering and view the creativity and artistry in that endeavour as asthetically pleasing also. Don't neglect them, and don't sterotype factory visits as ugly, and not useful.