Ascientific investigation is replicable if

Scientific investigations need to be replicable for many reasons like: It allows scientists to discover errors and shows results that may have happened in early year. It is also better so scientists know that the data is accurate and that the results will be reliable. 

Answer (d) valerie rides her bike south at 8 kilometers per hour///owen jogs south at 8 kilometers per hour ;

Answer sample (c); // would be best because the percentage of the energy in an incident wave that remains in a reflected wave from this material is the smallest;