You can also use a subquery to return the max
modified date for each person_id
and then join that result to your table to get the rows with the max date:
select t1.id,
t1.person_id,
t1.name,
t1.qualification,
t1.created,
t1.modified,
t1.version
from yourtable t1
inner join
(
select person_id, max(modified) MaxMod
from yourtable
group by person_id
) t2
on t1.person_id = t2.person_d
and t1.modified = t2.maxmod