Explanation:

- Element 106: This is the artificial element named seaborgium (Sg) after Glenn T. Seaborg. It was discovered by American researchers and is part of the transactinide series.

- Element 97: Known as berkelium (Bk), it does not honor Seaborg. It was discovered earlier at the University of California, Berkeley.

- Element 90: Identified as thorium (Th), it is a naturally occurring element, not named after Seaborg.

- Element 103: Known as lawrencium (Lr), named after Ernest Lawrence, not Seaborg.