Scientists often want to know if the genetically transformed organism can pass its new traits on to its offspring and future generations. to get this information, which would be a better candidate for your investigation, an organism in which each new generation develops and reproduces quickly, or one that does this more slowly

Quickly

Explanation:

The more quickly that a new generation of organisms develops and reproduces the faster that you will be able to observe whether the new traits  have been passed on to the new generation or not, and so on if you want to see this effect over several generations. For example, if you have genetically modified corn, you just have to wait one year to see if next year's generation of corn will have the modified trait or not. Conversely, if you geneticall modify an apple, you have to wait several years until the new generation of apples mature and are able to flower and produce the next generation of apple embryos.