Final answer:
The spider sculpture 'Maman' by Louise Bourgeois has a head proportionate to its massive dimensions of 895 x 980 x 1160 cm, making it much larger than any of the options provided in the question.
Step-by-step explanation:
The student's question refers to the size of the head of a spider sculpture known as Maman. This sculpture is a larger-than-life creation by the artist Louise Bourgeois, known for her impressive works which often draw from personal emotional experiences. The spider sculptures, including the one cited as Maman, were constructed in various sizes by Bourgeois to pay homage to her mother. The reference to a 'spider-girl' isn't directly connected to her work, so it's essential to clarify that Bourgeois's Maman sculpture measures a massive 895 x 980 x 1160 cm, with the head of the spider proportionate to this size. Therefore, it would be much larger than a ram's head, a maiden's head, a pea, or a small stone.
To be more specific, since the Maman sculpture is a bronze piece with extraordinary measures, the head of the spider would be much larger than a human head, contradicting all the provided size options in the student's question. Instead, it might resemble the real-life size of a smaller animal's body or even larger. This is a reflection of Bourgeois's perspective of spiders as patient, methodical creatures, much like her own mother.