What are the arguments that the joint tenancy was not severed by Martin Hendrickson’s declaration and thus the property passed to Solveig Hendrickson by survivorship upon Martin Hendrickson’s death?

On June 30, 2008, Martin Hendrickson and Solveig
Hendrickson were married, and on January 3, 2009, a home
previously owned by Martin was conveyed to them as joint
tenants and not as tenants in common. Solveig Hendrickson
paid no part of the consideration for the premises. On
August 3, 2016, Martin Hendrickson duly executed a Declara-
tion of Election to Sever Survivorship of Joint Tenancy by
which he endeavored to preserve an interest in the premises
for Ruth Halbert, his daughter by a previous marriage. On the
same day, he executed his last will and testament, by the terms
of which he directed that his wife, Solveig Hendrickson,
receive the minimum amount to which she was entitled under
the laws of the State of Minnesota. Martin Hendrickson died
with a valid will on October 9, 2016.
a. What are the arguments that the joint ownership was
severed by Martin Hendrickson’s declaration, thus
creating a tenancy in common?
b. What are the arguments that the joint tenancy was not
severed by Martin Hendrickson’s declaration and thus the
property passed to Solveig Hendrickson by survivorship
upon Martin Hendrickson’s death?
c. Which argument should prevail? Explain.