Okay, let me try to work through this question. The question is about determining the sex of skeletal remains based on pelvic characteristics. The key points given are that the ilium, ischium, and pubis have just started to fuse, the subpubic angle is 60 degrees, and the pelvic brim is heart-shaped.

First, I remember that in humans, the pelvis has distinct differences between males and females. The pelvis is wider in females to accommodate childbirth. The subpubic angle is a key feature here. From what I recall, in females, the subpubic angle is typically greater than 90 degrees because the pubic bones are more flared. A 60-degree angle seems more like a male pelvis.

The pelvic brim shape is another clue. A heart-shaped (or oval) pelvic brim is characteristic of the male pelvis. In females, the pelvic brim is more circular or oval but not heart-shaped. Also, the fusion of the pelvic bones—when do they fuse? I think the ilium, ischium, and pubis start to fuse in the late teens, around 15-18 years for females and a bit later for males. But the question mentions they've just started to fuse, which might indicate the individual was in their late teens or early 20s. However, the main question here is about sex determination, not age.

So putting it all together: subpubic angle less than 90 degrees, heart-shaped pelvic brim, and the fusion stage. These are all more indicative of a male pelvis. The options were A-D, but the correct answer is male. Wait, the options weren't listed, but the correct answer given is probably male. Let me check if I missed any other clues. Also, the heart-shaped brim is a classic male feature. The female pelvis has a more circular brim. The subpubic angle in males is indeed less than 90 degrees, so 60 degrees fits. The other options would have different angles and brim shapes. So the correct answer is male.

**Core Concept**
Sex determination from skeletal remains relies on pelvic morphology. The female pelvis is adapted for childbirth, featuring a broader subpubic angle (>90°) and a circular pelvic brim. Male pelves have a heart-shaped brim and a subpubic angle 90° and a circular pelvic brim, not heart-shaped.
**Option B:** A juvenile pelvis lacks fused bones entirely, as fusion begins in adolescence.
**Option C:** An elderly pelvis shows degenerative changes (e.g., osteoarthritis), not fusion onset.
**Option D:** Non-human pelvises have distinct morphologies (e.g., narrower sacrum in quadrupeds), unrelated to human sexual dim

✓ Correct Answer: C. 14-year-old male