Final answer:
A 100% transmittance result on a spectrophotometer indicates no absorption at that wavelength; however, it is an unexpected result for a red dye, which typically absorbs in the green to blue region and not at 380 nm.
Step-by-step explanation:
If a spectrophotometer is set at an absorbance of A-380 and records a 100% transmittance for a RED dyed petal, it means that all of the light at this wavelength is passing through the sample without any absorption occurring. However, this result is quite unexpected for a red dye because red dyes typically absorb light in the green to blue region of the spectrum (around 500-600 nm) and not in the near-ultraviolet region (380 nm), which would normally be absorbed by violet compounds.
The correct answer to what we would say about the results is option (c): It would be 100 percent. However, we must consider the potential reasons for this unexpected result, which could include an incorrect setting on the spectrophotometer, a malfunction of the device, or perhaps the petal does not contain any dye molecules that absorb at 380 nm.