Diastasis recti is most commonly seen in which of the following groups?

Diastasis recti is the condition characterized by the separation of the rectus abdominis muscles along the midline of the abdomen. This condition is most commonly observed in infancy, due to the natural separation of the abdominal muscles during fetal development and childbirth, as well as in multiparous women, who have experienced multiple pregnancies. During pregnancy, the growing uterus can stretch the abdominal wall, leading to a weakening of the connective tissue and subsequent separation of the rectus muscles.

In infants, diastasis recti may resolve on its own as the child grows and the muscles strengthen. In multiparous women, the condition can persist postpartum due to muscle fatigue and the stretching effect of multiple pregnancies.

The other groups mentioned are less commonly associated with this condition. Single males over 40 may experience abdominal wall issues, but diastasis recti is not typically prevalent in this demographic. Children with obesity can have various abdominal complications, but diastasis recti specifically is not a primary concern. Non-pregnant women generally do not experience this condition to the same extent as postpartum women or infants. Therefore, option A is the most accurate representation of the primary groups affected by diastasis recti.