Which hypothesis is testable using a scientific experiment? O A. Ancient people liked iron tools better than copper tools. O B. Copper statues look prettier than iron statues. O C. A 100 g iron bar is worth more money than a 100 g copper bar. O D. A copper wire conducts electricity better than an iron wire.

Astudent pours 10.0 g of salt into a container of water and observes the amount of time it takes for the salt to dissolve. she then repeats the process using the same amounts of salt and water but this time she slowly stirs the mixture while it is dissolving. the student performs the experiment one more time but this time she stirs the mixture rapidly. the dependent variable in this experiment is: time for salt to dissolve speed of stirring amount of water mass of salt