What type of soil contains 27% to 40% clay and 20% to 45% sand?

The correct identification of soil containing 27% to 40% clay and 20% to 45% sand points to clay loam. Clay loam is recognized for its balanced composition that includes a significant amount of clay, which is critical for improving water retention and soil structure. It also has enough sand content to facilitate drainage and air circulation, which are essential for root health and microbial activity.

The proportions specified in the question characterize clay loam's ability to retain moisture while still allowing for adequate drainage, making it suitable for a variety of plants. This soil type is often considered ideal for gardening and agricultural practices due to its versatility and responsiveness to cultivation techniques.

Other types such as sandy loam, loamy sand, and silty clay do not fit the clay content and sand ratio required in the question, thus confirming that clay loam is the correct classification.