A researcher is interested in developing a model to predict first-grade reading achievement. She includes in her model the following four factors: (a) the child's level of language development, (b) the highest level of education of a parent in the child's household, (c) the amount of time that the parent reads with the child, and (d) the quality of teaching that the child has received. The child's level of language, the quality of teaching, and the amount of time a parent reads to the child correlate with reading achievement. The highest level of education correlates with the amount of time the parent reads with the child but does not correlate with reading achievement. Which of the following variables only has an indirect effect on reading achievement? Group of answer choices parent education time joint reading quality of teaching language development