Which strategy is an example of how companies may upgrade themselves to meet changing customer preferences? a. doing door-to-door sellingb. using billboards to advertise the productsc. making online shopping services availabled. giving discounts on products

Which of the following types of stars is most likely to end up as a supernova? in graph a, the curve peaks at 800 nm, in the red section of the visible light spectrum. in graph b, the curve peaks at 550 nm, in the green section of the visible light spectrum. in graph c, the curve peaks at 450 nm, in the blue section of the visible light spectrum. in graph d, the curve peaks at 300 nm, in the violet section of the visible light spectrum. a b c d