Quizzical Pursuit - The Architecture Puzzler

Architecture Puzzler This Week

According to "American School & University" magazine, public school districts across the United States put more than $17 billion worth of construction in place in 1998. On average the construction cost per student in a new high school was about a) $8,500?
b) $19,300?
c) $24,800?

In older buildings with thin-stone anchorage systems using carbon steel shims and anchors, the sealants occasionally fail and the steel can corrode.

Which statement correctly explains this?

a) The corroded steel is greater in volume than uncorroded steel, and joints inadequate to accommodate this volume increase sometimes fail.

or