A researcher is studying the effects of three different types of fertilizers on crop yield. He uses a different fertilizer on three different plots of land with the same type of soil and observed the yield for a year. Based on this scenario, consider the following statements:

(a) The researcher's study is a form of one-way ANOVA.
(b) In this study, the independent variable is the type of fertilizer.
(c) If the researcher wants to control for variations in temperature and rainfall, he would use Analysis of Covariance (ANCOVA).
(d) Assumptions of homogeneity of variance and normality are irrelevant for this analysis.

Which of the statements are correct?