Which best explains why the pencil seems bent?

a. light travels slower in air than glass

b. light travels faster in air than in water.

c. light travels at the same speed in all matter

d. light travels at different speeds in water and in glass.

An electric power distributor charges residential customers $0.10 per kilowatt-hour (kwh). the company advertises that "green power" is available in 150 kwh blocks for an additional $4 per month. (green power is generated from solar, wind power, and methane sources.) if a certain customer uses an average of 391 kwh per month and commits to one monthly 150 kwh block of green power, what is her annual power bill